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Bellamy M, Chu B, Serencsits B, Quinn B, Prasad K, Altamirano J, Williamson M, Miodownik D, Abrahams N, Chen F, Bierman D, Wutkowski M, Carter L, Dauer L. Impact of shield location on staff and caregiver dose rates for I-131 radiopharmaceutical therapy patients. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2023; 43:033501. [PMID: 37413983 DOI: 10.1088/1361-6498/ace4d4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 07/06/2023] [Indexed: 07/08/2023]
Abstract
The goal of this study is to investigate the effect of the location and width of a single lead shield on the dose rate of staff and caregivers in a hospital room with an I-131 patient. The best orientation of the patient and caregiver relative to the shield was determined based on minimizing staff and caregiver radiation dose rates. Shielded and unshielded dose rates were simulated using a Monte Carlo computer simulation and validated using real-world ionisation chamber measurements. Based on a radiation transport analysis using an adult voxel phantom published by the International Commission on Radiological Protection, placing the shield near the caregiver yielded the lowest dose rates. However, this strategy reduced the dose rate in only a tiny area of the room. Furthermore, positioning the shield near the patient in the caudal direction provided a modest dose rate reduction while shielding a large room area. Finally, increased shield width was associated with decreasing dose rates, but only a four-fold dose-rate reduction was observed for standard width shields. The recommendations of this case study may be considered as potential candidate room configurations where radiation dose rates are minimized, however these findings must be weighed against additional clinical, safety, and comfort considerations.
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Affiliation(s)
- M Bellamy
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - B Chu
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - B Serencsits
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - B Quinn
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - K Prasad
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - J Altamirano
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - M Williamson
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - D Miodownik
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - N Abrahams
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - F Chen
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - D Bierman
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - M Wutkowski
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - L Carter
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
| | - L Dauer
- Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, United States of America
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Hartmann H, Andreeff M, Claußnitzer J, Kotzerke J, Brogsitter C. Determination of Radiation Exposure of Individuals in the Population by Patients after Radioiodine Therapy - Comparison of two Measurement Systems. ROFO-FORTSCHR RONTG 2023; 195:605-612. [PMID: 37160149 DOI: 10.1055/a-2015-0475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
According to the requirements of radiation protection legislation, patients may only be discharged from the nuclear medicine therapy ward if it is ensured that the cumulative radiation exposure of the population is below 1 mSv per year. In the present study, dose measurements of patients after radioiodine therapy (RIT) and their relatives are to be used to prove that the radiation exposure resulting from the medical application is low and that the legal framework conditions are complied with. Furthermore, the results allow conclusions to be drawn about the measurement accuracy of the dosimeters used. METHODS In 147 patients after RIT and their relatives, the dosage was measured over 14 days with different measuring systems. Finger ring dosimeters (FRD) were worn during the whole day, furthermore the dose was determined by non-official OSL and TLD dosimeters during the sleep phase. RESULTS 88 data sets were used for the final analysis. With the FRD, dose values between 0.1-50 mSv were determined for the patients. As expected, the finger ring dose of the relatives was significantly lower, averaging 0.75 mSv compared to 10 mSv for the patient. For the TLD and OSL used in the sleep phase, the measured values were in the same range. The reproducibility of the measurement results was significantly better for the OSL than for the TLD. CONCLUSION Despite method-related measurement uncertainties, it can be concluded that the exposure dose of patients' relatives after radioiodine therapy is low and that the legal requirements are met. Moreover, the now official OSL dosimeters represent a more accurate and for the chosen measurement task better suited measurement system than the TLD. KEY POINTS · The exposure dose of patients' relatives after radioiodine therapy is low.. · The requirements of radiation protection legislation after discharge from the nuclear medicine therapy ward are complied with. · OSL dosimeters are a accurate and for the measurement task suited system. CITATION FORMAT · Hartmann H, Andreeff M, Claußnitzer J et al. Determination of Radiation Exposure of Individuals in the Population by Patients after Radioiodine Therapy - Comparison of two Measurement Systems. Fortschr Röntgenstr 2023; 195: 605 - 612.
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Affiliation(s)
- Holger Hartmann
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Michael Andreeff
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Jörg Claußnitzer
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Jörg Kotzerke
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Claudia Brogsitter
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
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Bellamy M, Chu B, Serencsits B, Quinn B, Prasad K, Altamirano J, Williamson M, Miodownik D, Abrahams N, Chen F, Bierman D, Wutkowski M, Dauer L. SUBSTANTIAL EXTERNAL DOSE RATE VARIABILITY OBSERVED IN A COHORT OF LU-177 PATIENTS INDEPENDENT OF BMI AND SEX. RADIATION PROTECTION DOSIMETRY 2022; 198:1476-1482. [PMID: 36138119 PMCID: PMC9667277 DOI: 10.1093/rpd/ncac187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 07/06/2022] [Accepted: 08/23/2022] [Indexed: 06/16/2023]
Abstract
External dose rates were measured 1 m away from 230 Lu-177 patients to characterise the variability in normalised dose rates as a function of administered activity, body mass index (BMI) and sex. The largest dose rate observed was 0.07 mSv/h associated with an administered activity of 7.2 GBq. Substantial variability was found in the distribution of the normalised dose rate associated that had an average of 0.0037 mSv/h per GBq and a 95% confidence interval of 0.0024-0.0058 mSv/h per GBq. Based on this study, estimating the patient dose rate based on the Lu-177 gamma exposure factor overestimates the dose rate by a factor of 2. A statistically significant inverse relationship was found between the patient dose rate and patient BMI and an empirically derived equation relating these two quantities was reported. On average, male patient dose rates were 3.5% lower than female dose rates, which may be attributed to the larger average BMI of the male patient group.
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Affiliation(s)
| | - Bae Chu
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Brian Serencsits
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Brian Quinn
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - K Prasad
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - J Altamirano
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Matthew Williamson
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Daniel Miodownik
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Natalie Abrahams
- Siena College, 515 Loudon Road, Loudonville, New York, NY 12211, USA
| | - Fanny Chen
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - David Bierman
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - M Wutkowski
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
| | - Lawrence Dauer
- Department of Medical Physics, Memorial Sloan Kettering, 1275 York Avenue, New York, NY 10065, USA
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Aziz L, Dewji S. UPDATED AGE-SPECIFIC EXTERNAL DOSE AND EXPOSURE RATE COEFFICIENTS FOR 131I PATIENT RELEASE. RADIATION PROTECTION DOSIMETRY 2022; 198:311-324. [PMID: 35437606 DOI: 10.1093/rpd/ncac049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/20/2022] [Accepted: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Updated effective dose rate and exposure rate coefficients for age-specific receptors representing members of the public were computed for external exposures from age-specific patients administered 131I to treat thyroid dysfunction for patient release evaluation. Coefficients were compared to the simplified point source method described by United States Nuclear Regulatory Commission Regulatory Guide (RG) 8.39, which does not consider age-specific parameters, morphometry or time-dependent 131I biodistribution. Monte Carlo age-specific phantom simulations were correlated with modified continuous voiding patient biokinetic models approximating age-specific dose and exposure rates as a function of time postadministration. Dose rates resulted in an overapproximation by a factor of ~3 from differentiated thyroid cancer patients (5% uptake) and by ~2 from hyperthyroid patients (80%) at 8 h postadministration compared to RG8.39. This study provides a paradigm where age-specific morphometry and biokinetic integration must be jointly considered when developing patient release guidelines for 131I and future radionuclide therapies.
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Affiliation(s)
- L Aziz
- Department of Nuclear Engineering, Texas A&M University, 3133 TAMU, College Station, TX 77843-3133, USA
| | - S Dewji
- Nuclear and Radiological Engineering and Medical Physics Programs, Georgia Institute of Technology, 770 State Street, Atlanta, GA 30332-0405, USA
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AlSadi R, Aziz LC, Bohan M, Dewji S, Bouhali O, Djekidel M. Clinical Management of End-Stage Renal Disease Patients on Dialysis Receiving Radioactive Iodine Treatment. Clin Nucl Med 2021; 46:977-982. [PMID: 34661559 DOI: 10.1097/rlu.0000000000003915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Radioactive iodine (RAI) is used to treat thyroid cancer patients with a clear paradigm for most patients. End-stage renal disease (ESRD) patients pose several challenges when undergoing RAI treatment, primarily due to the lack of renal clearance. We retrospectively report our experience with RAI treatment in a cohort of patients with ESRD and provide a set of recommendations on aspects such as the need for adjusted dose activity, balancing scheduling between RAI therapy and dialysis, and radiation safety precautions. PATIENTS AND METHODS In this study, we report on 5 patients (6 cases), with ESRD on dialysis, treated with RAI for thyroid cancer. Retention measurements to determine individual biological clearance of RAI from the patient's body before and after dialysis sessions were assessed using external exposure dose rates measured at 1 m. RESULTS Delayed biological clearance of RAI, after the first hemodialysis session, resulted in a longer RAI effective half-life as a consequence of longer retention periods, consistent with observations reported in scientific literature. To achieve a much closer radiation exposure compared with a nondialysis patient, one would recommend administering ~20%-30% of the dose activity normally administered to a thyroid cancer patient based on their medical history, histopathology, and uptake with the appropriate dialysis schedule. CONCLUSIONS Special precautions should be taken with the administration of RAI in ESRD patients by adjusting the prescribed dose activity, dialysis sessions, and paying special attention to wastes. Pooling data from multiple centers may be useful to build a consensus and substantiated recommendations.
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Affiliation(s)
- Rahaf AlSadi
- From the Science Department, Texas A&M University at Qatar, Doha, Qatar
| | - Landon C Aziz
- Department of Nuclear Engineering, Texas A&M University, College Station, TX
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Thao NTP, Trung NT, Duy NK, Danh NT, Anh PT, Son ND. ADDING TWO NEW CONTACT CIRCUMSTANCES TO 'MERGED PHANTOM TOOL' AND A TECHNIQUE TO CONVERT STRUCTURE INFORMATION SEGMENTED BY THE CARIMAS SOFTWARE INTO GEANT4 GEOMETRY. RADIATION PROTECTION DOSIMETRY 2020; 190:412-418. [PMID: 32909038 DOI: 10.1093/rpd/ncaa117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/05/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Two new contact circumstances called 'stand-lie' and 'front-rear' are implemented to the merged phantom tool. To allow more flexibility for users when they calculate the dose for a volume of interest (VOI) with arbitrary geometry, an optional utility to convert segmented structure information from the CARIMAS software into parallel geometry of GEANT4 is provided. The effective dose for a person who has been in contact with a male patient being treated for thyroid cancer with 131I is calculated for four circumstances: opposite, side by side, stand-lie and front-rear. The biggest dose is the 'opposite' circumstance and the smallest one is the 'stand-lie' circumstance. Using the dose distribution in the patient's body and applying the right circumstance should be done to optimise the dose calculation for the contact person.
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Affiliation(s)
- Nguyen Thi Phuong Thao
- Vietnam Atomic Energy Institute, Hoan Kiem, Ha Noi, Viet Nam
- Nguyen Huu Huan High School, Thu Duc District, HCM City, Viet Nam
| | | | | | | | - Pham Tien Anh
- Nguyen Huu Huan High School, Thu Duc District, HCM City, Viet Nam
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Dewji SA. Response to Fisher. HEALTH PHYSICS 2020; 119:367. [PMID: 32740395 DOI: 10.1097/hp.0000000000001317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- Shaheen A Dewji
- Department of Nuclear Engineering Texas A&M University 3133 TAMU College Station, TX 7843-3133
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Foreman C, Dewji S. Estimation of External Dose Rates to Hotel Workers from bed linens Contaminated by 131I Patients. HEALTH PHYSICS 2020; 118:615-622. [PMID: 31658163 DOI: 10.1097/hp.0000000000001141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Iodine-131 is commonly used in medical diagnosis and therapy for patients with hyperthyroidism or differentiated thyroid cancer. Following treatment, patients may recuperate in a hotel room to avoid exposing family members. The main purpose of this study was to estimate external effective dose rate coefficients to a hotel worker who handles potentially contaminated bed linens due to secretions from I patients as sweat or urine. The external dose rate estimates were derived using Monte Carlo radiation transport code and the phantom with movable arms and legs to model a housekeeper standing in an upright position holding a pile of bed linens. Simulations further integrated the body burden of time-dependent biokinetic metabolism of I in the patient's body, differentiating between biokinetic excretion models of hyperthyroid vs. cancer patients. Organ absorbed dose rate and effective dose rate coefficients were calculated for three scenarios of bed linen contamination and estimated out to 5 d postadministration and compared to past I patient contamination measurements.
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Affiliation(s)
- C Foreman
- Department of Nuclear Engineering, Center for Nuclear Security Science and Policy Initiatives, Texas A&M University, College Station, TX 77843
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9
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Griffin KT, Cuthbert TA, Dewji SA, Lee C. Stylized versus voxel phantoms: a juxtaposition of organ depth distributions. Phys Med Biol 2020; 65:065007. [PMID: 32059205 DOI: 10.1088/1361-6560/ab7686] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
For external irradiation, the variability in organ dose estimation found between computational phantom generations arises particularly from the differences in organ positioning. This work represents the first effort to quantify the differences in organ depth below the body surface between a stylized and voxel phantom series. Herein, the revised Oak Ridge National Laboratory stylized phantom series and the University of Florida/National Cancer Institute voxel phantom series were compared. Both series include whole-body models of the newborn; the 1-, 5-, 10-, and 15-year-old; and the adult human. Organ depths from eight different directions applicable to external irradiation geometries were computed: antero-posterior, postero-anterior, left and right lateral, rotational, isotropic, cranial and caudal directions. Organ depths in the stylized phantoms were computed using a ray-tracing technique available through Monte Carlo radiation transport simulations in MCNP6. Organ depths in the voxel phantom were found using phantom matrix manipulation. Resultant organ depths for both series were plotted as distributions; available are twenty-four organs and two bone tissue distributions for each of six phantom ages and in each of the eight directional geometries. Quantitative data descriptors (e.g. mean and median depths) were also tabulated. For demonstration purposes, a literature review of relevant stylized versus voxel comparison works was performed to explore where the quantification of organ depth differences can provide further insight or evidence to study conclusions. The entire dataset of organ depth distributions and their data descriptors can be found in online supplementary files.
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Affiliation(s)
- Keith T Griffin
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, United States of America
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Edis N, Tamam MO. THE COMPARISON OF THE EXTERNAL DOSE RATE MEASUREMENT OF CHILDREN AND ADOLESCENT PATIENTS WITH ADULT PATIENTS TREATED WITH RADIOIODINE THERAPY. RADIATION PROTECTION DOSIMETRY 2019; 184:168-173. [PMID: 30452694 DOI: 10.1093/rpd/ncy195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/24/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
The aim of this study is to evaluate the radiation safety of caregiving people contacting the child and adolescent patients with thyroid cancer who received radioactive iodine-131 (RIT) treatment by comparison with external dose rate measurements of adult patients according to their administered activities and days of hospitalization. We retrospectively evaluated external dose rate measurement of 158 children and adolescent patients and 158 adult patients. During the RIT, the hospitalization time were grouped as 2, 3 and 4 d, and the administered activities as <3700, 3700 and >3700 MBq. The values of external dose rate measurements of children and adolescents were statistically significantly higher than the adult group. Different approaches in radiation safety rules are required for children and adolescents. In terms of radiation safety, we suggest that more specific regulations for family members and caregivers should be established and informed.
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Affiliation(s)
- Nurcan Edis
- Department of Nuclear Medicine, University of Health Science, Okmeydani Training and Research Hospital, Istanbul, Turkey
| | - Muge Oner Tamam
- Department of Nuclear Medicine, University of Health Science, Okmeydani Training and Research Hospital, Istanbul, Turkey
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Zhao WJ, Lv QG, Fei Y, Zhao Z, Zhang YW. Prognostic factors analysis for a calculated dose of 131I therapy in Graves' disease in China. GAZZETTA MEDICA ITALIANA ARCHIVIO PER LE SCIENZE MEDICHE 2019. [DOI: 10.23736/s0393-3660.17.03708-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Barnes JA, de la Guardia M, Easley T, Downs H, Mims S, Nielson K, Granger M. Radiation Safety Aspects of Iodine-131 metaiodobenzylguanidine (131I mIBG) Therapy Program Startup. HEALTH PHYSICS 2018; 115:776-786. [PMID: 33289999 DOI: 10.1097/hp.0000000000000905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
As a medical center without a pre-existing radiopharmaceutical therapy program, it was a daunting endeavor to implement a I metaiodobenzylguanidine (mIBG) high-dose treatment regimen. It took several years of planning with hospital administration, vendors, and Texas Department of Health Radiological Control regulators to establish a viable program. Effective communication between physicians, nursing, nuclear medicine, environmental services, maintenance, and other support staff is essential and paramount for the successful execution and continued sustainability of the mIBG therapy program. Besides providing an effective treatment for patients, an additional goal for the program is to keep radiation exposure As Low As Reasonably Achievable (ALARA) for staff and patient caregivers. As such, start-up presented many training, logistical, and radiation safety challenges. The location of the isolation room and shielding specifications were designed to keep radiation exposure to public access areas to less than 2 microsieverts per hour. Before the first patient was treated the policies and procedures for training, radiation safety, product quality control, and infusion process needed to be developed, tested, and approved by various committees. Furthermore, a similar process was required for developing room set-up, post therapy cleanup, and waste storage procedures. Throughout the maturation process of the program, the departments involved have found that our safety culture has continually improved by the re-enforcement of knowledge and lessons learned, as both the ancillary and treatment staff grew more confident in each other's ability during more patient treatments are performed. This article describes the process and lessons learned during the time leading up to the startup and early years of the mIBG therapy program.
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Affiliation(s)
- J A Barnes
- 1Cook Children's Medical Center, Fort Worth, TX
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13
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Bales K, Dewji S, Sanchez E. Comparison of neutron organ and effective dose coefficients for PIMAL stylized phantom in bent postures in standard irradiation geometries. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2018; 57:375-393. [PMID: 30167867 DOI: 10.1007/s00411-018-0751-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present work, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields. Simulations were conducted using the Oak Ridge National Laboratory's articulated stylized adult phantom, "Phantom wIth Moving Arms and Legs" (PIMAL) software package, and the Monte Carlo N-Particle (MCNP) version 6.1.1 radiation transport code. Organ doses were compared for the upright and bent (45° and 90°) phantom postures for neutron energies ranging from 1 × 10- 9 to 20 MeV for the ICRP Publication 116 external exposure geometries-antero-posterior (AP), postero-anterior (PA), and left and right lateral (LLAT, RLAT). Using both male and female phantoms, effective dose coefficients were computed using ICRP Publication 103 methodology. The resulting coefficients for articulated phantoms were compared to those of the upright phantom. Computed organ and effective dose coefficients are discussed as a function of neutron energy, phantom posture, and source irradiation geometry. For example, it is shown here that for the AP and PA irradiation geometries, the differences in the organ coefficients between the upright and bent posture become more pronounced with increasing bending angle. In the AP geometry, the brain dose coefficients are expectedly higher in the bent postures than in the upright posture, while all other organs have lower dose coefficients, with the thyroid showing the greatest difference. Overall, the effective dose estimated for the upright phantom is more conservative than that for the articulated phantom, which may have ramifications in the estimation or reconstruction of radiation doses.
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Affiliation(s)
- K Bales
- Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN, USA
- Department of Nuclear Engineering, University of Tennessee, Knoxville, Knoxville, TN, USA
| | - S Dewji
- Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN, USA.
| | - E Sanchez
- Oak Ridge National Laboratory, Center for Radiation Protection Knowledge, Oak Ridge, TN, USA
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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Zerdoud S, Leboulleux S, Clerc J, Leenhardt L, Bournaud C, Al Ghuzlan A, Keller I, Bardet S, Giraudet AL, Groussin L, Sebag F, Garrel R, Lamy PJ, Toubert ME, Mirallié É, Hindié E, Taïeb D. Traitement par iode 131 des cancers thyroïdiens différenciés : recommandations 2017 des sociétés françaises SFMN/SFE/SFP/SFBC/AFCE/SFORL. MEDECINE NUCLEAIRE-IMAGERIE FONCTIONNELLE ET METABOLIQUE 2017. [DOI: 10.1016/j.mednuc.2017.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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